In the application of the previous art regarding the subject device, including the art disclosed Johnson U.S. Pat. No. 3,494,092, and including improvements to the art, for which patents have been applied, and with particular reference to its application by unskilled labor for a U.S. Air Force Project in Turkey, it has been necessary to develop an improved method of applying the lifting force directly to the hinges without the hinges extending above the surface of the slab. This being necessary so as to not interfere with the casting of overlying units on top of the first cast unit. In addition, it is necessary to develop an improvement that would control the height of the walls and to preclude the spreading of the forms during the pouring of the concrete, which had resulted in walls of unequal heights. In addition, it is necessary to develop an insert that would not be knocked out of alignment during the concrete pour, which condition resulted in the development of overstressing during the elevating of the units. The subject invention solves the problems which had stalemated the engineers and others skilled in the art of constructing buildings by this method. The subject invention does so in a simple direct method which should contribute substantially to the efficiency and economy of the folding construction method.